1. Technical Field
The present invention relates in general to the electroplating of workpieces and, in particular, to an improved system, method, and apparatus for the continuous electroplating of the exteriors and/or interiors of elongated workpieces such as shafts and tubes.
2. Description of the Related Art
Historically, the metallic electroplating of parts or workpieces that more than 20 feet in length has been problematic and expensive due to the very large plating tanks that are required, and the significant volume of plating chemicals needed to fill the tanks. As the plating chemicals are toxic and have a finite life, there is an additional cost incurred for proper disposal according to EPA requirements.
In addition, large plating tanks have very large electrical power requirements. With a large tank plating operation, the entire part or surface of a workpiece is plated at one time. To successfully plate the surface of a workpiece, a specific amount of power per unit surface area is required, which is also known as the current density. If the entire part is to be plated at one time, such as in the case of large plating tanks, a larger power supply would be required.
For example, some offshore drilling and production platforms use ram-style tensioners having a 28 to 30 foot stroke length that is exposed to acids, etc., that cause corrosion. These types of workpieces are too long for conventional plating techniques. Thus, an improved process for applying plating metals with a different technique than conventional “tank plating” processes would be desirable. In particular, the ability to plate only small areas of the workpiece at a time, rather than all or large sections of a workpiece would be especially desirable.